Traditional microwave ovens usually comprise a single cooking cavity in which a foodstuff to be cooked is placed. The number of foodstuffs that can be prepared at the same time in such traditional microwave ovens is therefore limited and inadequate for many users. For example, preparing different foodstuffs that require different cooking parameters in a single cavity microwave oven may require the time to cook them sequentially rather than concurrently because of the different cooking parameters. Out of this need, microwave ovens with multiple cooking cavities were developed.
For example U.S. Publication No. 20130153570 discloses a microwave oven with two sub-cavities to simultaneously cook multiple foodstuffs with improved cooking evenness and cooking time. Each sub-cavity is provided with a microwave generator and feeding port to independently cook foodstuffs located therein. A removable dividing shelf between the sub-cavities attenuates microwave transmission between the sub-cavities. A sealing choke where the shelf meets the walls of the cavity aids the attenuation. However, transmission may still occur between the shelf and the door.